1 Blessed is the man
who walks not in the counsel of the wicked,
nor stands in the way of sinners,
nor sits in the seat of scoffers;
2 but his delight is in the law of the Lord,
and on his law he meditates day and night.
3 He is like a tree
planted by streams of water
that yields its fruit in its season,
and its leaf does not wither.
In all that he does, he prospers.
4 The wicked are not so,
but are like chaff that the wind drives away.
5 Therefore the wicked will not stand in the judgment,
nor sinners in the congregation of the righteous;
6 for the Lord knows the way of the righteous,
but the way of the wicked will perish. - Psalm 1:1-6
The whole of this psalm must be considered together. There is a clear and persuasive point to the entirety of this song from David. The psalm is split into two, the wise and the foolish or the righteous and the wicked. The psalm proscribes the idea that the very lives of these two are the same. They are not nor can they be confused to be. The fruits of the righteous and unrighteous are obvious and discernible (Matt 7:15-20).
Those who do not perish are known by their relationship to sinners (v. 1), their desired place of exaltation (v. 1) and what consumes their time (v. 2). In the end God knows them in the manner intimacy of a husband with his bride (Gen 4:1). God returns them to the garden of His presence (Gen 2:10; Rev 22:1-2). Those who will perish share none of these things. Nor are they known by God in intimacy.
Their lives are frailty that is fleeting (v. 4). They cannot stand the judgment (v. 5) for they have stood with sinners (v. 1). Their way cannot be known by God.